I am currently an art student at manchester metropolitan university in the u.k and my project is growing grass. I have recently heard of a technique that has been used by other artists were clay and grass are put together and then plastered onto an object and the grass grows through the clay. I would like to no how to do this as it would benefit me and my work.

The best advice comes from people with experience in the specific area. In other cases, people can suggest things that might work for lack of anybody with real experience.

I would mix in general purpose fertilizer and grass seed to the clay. Annual rye for a coarse, short lived grass that will grow no matter how badly you treat it. A perennial rye for a finer, longer lived grass. Red fescue if you don't want to have to mow as often.

Try a simple shape at first. No sense wasting a bunch of time on something that may not grow. Keep it moist. Clay will dry out, shrink, and crack. Maybe mist it every day with water containing Rapid-Grow. Play around, maybe you can become an expert on it.

Let me know how this works.

I was wondering is it a good idea to germinate the grass seeds before I mix them with the clay and if it is, what is the most quick and most effective way. I have seen people put seeds in tissue paper and cotton wool to germinate?

Grass seedlings are fragile, and I doubt they would survive beint mixed into clay.